Process for the production of xylenes

• Main Authors: MOLINIER, MICHEL, ANDREWS, JEFFREY L, BENDER, TIMOTHY PAUL, STANLEY, DENNIS J, TINGER, ROBERT G, WAGNER, GEORGE J
• Format: Patent
• Language: Chinese; English
• Published: 11.06.2017
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; CRACKING HYDROCARBON OILS; FUELS; LUBRICANTS; METALLURGY; MINERAL WAXES; ORGANIC CHEMISTRY; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; SEPARATION; TECHNICAL GASES CONTAINING CARBON MONOXIDE; TRANSPORTING

In a process for producing para-xylene, a toluene-containing stream is contacted with a methylating agent under conditions effective to convert toluene to xylenes and produce a methylated effluent stream. Para-xylene is recovered from the methylated effluent stream to produce a para-xylene depleted stream and part of the para-xylene depleted stream is contacted with a xylene isomerization catalyst under liquid phase isomerization conditions effective to produce a first isomerized stream, while part of the para-xylene depleted stream is contacted with a xylene isomerization catalyst under vapor phase isomerization conditions effective to produce a second isomerized stream. The first and second isomerized streams are then recycled to the para-xylene recovery step.